Many products are transported in bulk in open top tanks or bins. Wine grapes are often transported in this way from the field to the winery. Once at the winery the tank is unloaded, typically by tipping the tank into an appropriate receptacle. Having an open top aids both filling the tank in the field and emptying the tank at the winery.
One of the problems associated with transporting wine grapes is that the wine grapes often act like a slurry material when transported in large tanks. This tendency is accentuated when the grapes are mechanically harvested since mechanically harvested grapes are detached from their stems during harvesting. Thus, if the transport driver is not careful, and sometimes even if the driver exercises great care, the slurry like material may roll and surge within the tank thus allowing some of the grapes to leave the tank and be lost.